邮票上的物理学史⑨--牛顿

"牛顿由于发现了万有引力定律而创立了科学的天文学,由于进行了光的分解而创立了科学的光学,由于建立了二项式定律和无穷理论而创立了科学的数学,由于认识了力的本性而创立了科学的力学."恩格斯的这段话很好地总结了牛顿的科学业绩.为了纪念牛顿在科学上的伟大建树,许多国家发行了多枚一套的邮票.     

自由落体实验的改进

针对教材中自由落体实验操作的不稳定性,改进了实验,增强了实验操作的稳定性,提高了实验的精确度,减少了实验次数,节省了时间,提高了课堂效率.     

大统一理论:回顾与展望

本文系统地讨论了大统一理论的来龙去脉。回顾了大统一理论的发展历史,讨论了其发展现状及存在问题,指出了进一步发展的方向。本文重点介绍了SU(5)和SO(10)两个模型,讨论了Higgs场、规范等级、渐近自由、重正化等问题。文章进而讨论了一些有趣问题,比如提供了对宇宙重子起源的解释、计算了质子衰变寿命、论述了B-L是否守恒以及讨论了中子和中微子可能有的振荡现象等。     

物理实验开放式教学初探

网上预约实验实现了各校区资源共享、教学内容有弹性满足了不同层次学生的需求，开放式教学增强了教师的责任心，激发了学生学习的主动性和积极性，提高了实验教学质量，充分利用了实验室的资源，取得了较好的效果。     

双波段扫描辐射计的研制

介绍了一种新型小视场、高精度的双波段扫描辐射计。描述了系统的特点,分析了系统的总体方案。介绍了系统的工作原理,对系统的NETD进行了估算,对其探测器的选择、光学系统设计、调制系统设计、扫描机构设计、信号处理等方案进行了详细论述,对系统的标定和测量原理进行了分析,并给出了相应的计算公式。给出了系统的检测结果。     

地磁场测量实验教学设备的改造、替代及软件选取

介绍了周期幅值法测量地磁场的实验方法,指出了原实验设备存在的问题,同时提出了实验设备的改造方案,并详细介绍了如何软选取件模块.该工作降低了实验教学的维护成本,节约了因等待维护耗费的大量时间,保证了实验教学的顺利进行.     

La/酸化膨润土吸附剂的表征与除磷性能

以酸化改性膨润土为载体,采用浸泡法制备了稀土La掺杂的La/酸化膨润土吸附剂.通过XRD和FTIR对其结构进行了表征,探讨了膨润土的改性机理,研究了该吸附剂对废水的除磷性能.结果表明：酸化过程洗掉了膨润土中的杂质和氧化铝,稀土镧的掺杂在膨润土层间及表面引入了一定数量的羟基化合物,改善了膨润土的层间结构并生成了新的La-O-Si键,实现了La与膨润土的复合,提高了膨润土的吸附性能.     

控制环量设计涡轮的实验研究

采用控制环量方法设计了一单级涡轮。该方法打破了传统的设计规律,为验证该方法的可靠性进行了模型试验。在宽广的范围内测定了总特性;在设计点附近作了沿叶高效率分布及动叶进、出口速度三角形的测定。本文给出了主要试验结果并作了简要分析。结果表明基本上达到了设计要求,控制环量设计的主要特征得到了验证,该方法基本可行。     

微粒污垢剥蚀机制研究

本文分析了微粒污垢的形成过程，研究了其剥蚀机制，解释了出现污垢诱导期的原因，并重新定义了微粒污垢的诱导期．利用湍流猝发理论导出了一个新的微粒污垢分析模型，该模型的特点是以易测参数表示污垢热阻．在实验室进行了气侧微粒污垢的实验研究。积累了必要的微粒污垢数据并验证了分析模型的正确性．     

纳米流体脉动热管的流动与传热性能研究

建立了纳米流体脉动热管的分析模型,将相变传热项合理引入了汽塞能量微分方程;液塞动量方程中考虑了剪切力的影响;纳米流体的物性采用了当量处理方法.采用数值迭代方法进行了求解,得到了汽塞压力、温度、质量的变化波形,分析了波形的频率,进而解释了初始条件、重力等对脉动热管的流动与传热影响的机理.     

事件空间中力学系统的微分变分原理

研究事件空间中力学系统的微分变分原理.基于D'Alembert原理，建立了事件空间中力学系统的D'Alembert-Lagrange原理、Jourdain原理、Gauss原理和万有D'Alembert原理，给出了这些原理的Euler-Lagrange参数形式、Nielsen参数形式和Appell参数形式，并导出了万有D'Alembert原理的Mangeron-Deleanu参数形式. 关键词： 分析力学 事件空间 微分变分原理     

Uncertainty and complementarity in axiomatic quantum mechanics

In this work an investigation of the uncertainty principle and the complementarity principle is carried through. A study of the physical content of these principles and their representation in the conventional Hilbert space formulation of quantum mechanics forms a natural starting point for this analysis. Thereafter is presented more general axiomatic framework for quantum mechanics, namely, a probability function formulation of the theory. In this general framework two extra axioms are stated, reflecting the ideas of the uncertainty principle and the complementarity principle, respectively. The quantal features of these axioms are explicated. The sufficiency of the state system guarantees that the observables satisfying the uncertainty principle are unbounded and noncompatible. The complementarity principle implies a non-Boolean proposition structure for the theory. Moreover, nonconstant complementary observables are always noncompatible. The uncertainty principle and the complementarity principle, as formulated in this work, are mutually independent. Some order is thus brought into the confused discussion about the interrelations of these two important principles. A comparison of the present formulations of the uncertainty principle and the complementarity principle with the Jauch formulation of the superposition principle is also given. The mutual independence of the three fundamental principles of the quantum theory is hereby revealed.     

基于原子干涉仪的微观粒子弱等效原理检验

等效原理是广义相对论的两个基本假设之一,也是爱因斯坦对弱等效原理的推广.目前,大量实验证明弱等效原理在一定的实验精度内是成立的.将引力与标准模型统一起来的新理论都要求弱等效原理破缺,因此更高精度的弱等效原理检验具有重要的科学意义.本文介绍了原子干涉仪的原理,回顾了利用原子干涉仪开展微观粒子弱等效原理检验实验研究的历史和现状,介绍了双组分原子干涉仪检验弱等效原理实验涉及的振动噪声抑制、拉曼光移频与相位噪声抑制、四波双衍射拉曼跃迁原子干涉、信号探测与数据处理等关键问题及研究进展,分析了高精度微观粒子弱等效原理检验研究的发展趋势,介绍了长基线原子干涉仪、空间原子干涉仪、超冷原子源以及纠缠原子源制备等方面的研究动态,展望了微观粒子弱等效原理检验研究的发展前景.     

关于大学物理中“不确定原理”一节内容不同讲法的比较和建议

海森伯不确定原理是量子物理的基石之一,尽管物理学界对其基本意义仍有争论,但在大学物理课程教学过程中对该原理的讲述,无疑应该注重引导学生扬弃经典轨道概念、建立波粒二象性概念.然而目前国内多数教材对此原理的讲法,事实上仍然或明或暗地使用了经典轨道的概念,从而容易使学习者产生困惑,本文调查对比了国内外几十种教材对不确定原理的讲解和论述方法,在此基础上提出了该部分教材的修改和教学建议.     

Uniformity principle of temperature difference field in heat transfer optimization

The uniformity principle of temperature difference field is very useful in heat exchanger analyses and optimizations.In this paper, we analyze some other heat transfer optimization problems in the thermal management system of spacecrafts,including the cooling of thermal components, the one-stream series-wound heat exchanger network, the volume-to-point heat conduction problem, and the radiative heat transfer optimization problem, and have found that the uniformity principle of temperature difference field also holds. When the design objectives under the given constraints are achieved, the distributions of the temperature difference fields are uniform. The principle reflects the characteristic of the distribution of potential in the heat transfer optimization problems. It is also shown that the principle is consistent with the entransy theory. Therefore, although the principle is intuitive and phenomenological, the entransy theory can be the physical basis of the principle.     

Fermat principle for a nonstationary medium

One possible formulation of a variational principle of the Fermat type for systems with time-dependent parameters is suggested. In a stationary case, it reduces to the Mopertui-Lagrange least-action principle. A class of Hamiltonians (dispersion relations) is indicated, for which the variational principle reduces to the Fermat principle in a general nonstationary case. Hamiltonians that are homogeneous functions of momenta are in this category. For the important case of nondispersive waves (corresponding to Hamiltonians being homogeneous function of momenta order 1) the Fermat principle fully determines the geometry of the rays. Equations relating the variation of signal frequency with the rate of change of propagation time are established.     

Onsager principle as a tool for approximation

Onsager principle is the variational principle proposed by Onsager in his celebrated paper on the reciprocal relation.The principle has been shown to be useful in deriving many evolution equations in soft matter physics.Here the principle is shown to be useful in solving such equations approximately.Two examples are discussed:the diffusion dynamics and gel dynamics.Both examples show that the present method is novel and gives new results which capture the essential dynamics in the system.     

Irreversibility and entropy production in transport phenomena,III—Principle of minimum integrated entropy production including nonlinear responses

A new variational principle of steady states is found by introducing an integrated type of energy dissipation (or entropy production) instead of instantaneous energy dissipation. This new principle is valid both in linear and nonlinear transport phenomena. Prigogine’s dream has now been realized by this new general principle of minimum “integrated” entropy production (or energy dissipation). This new principle does not contradict with the Onsager–Prigogine principle of minimum instantaneous entropy production in the linear regime, but it is conceptually different from the latter which does not hold in the nonlinear regime. Applications of this theory to electric conduction, heat conduction, particle diffusion and chemical reactions are presented.     

On the equivalence principle in quantum theory

The role of the equivalence principle in the context of non-relativistic quantum mechanics and matter wave interferometry, especially atom beam interferometry, will be discussed. A generalised form of the weak equivalence principle which is capable of covering quantum phenomena too, will be proposed. It is shown that this generalised equivalence principle is valid for matter wave interferometry and for the dynamics of expectation values. In addition, the use of this equivalence principle makes it possible to determine the structure of the interaction of quantum systems with gravitational and inertial fields. It is also shown that the path of the mean value of the position operator in the case of gravitational interaction does fulfill this generalised equivalence principle.     

A study of constraints on the constitutive relationships of electro magnetic medium based on generally acknowledged truths

1 Introduction With the new synthetic material coming forth, many scholars pay more and more at-tention to the issue of the probable forms of electromagnetic (EM) medium constitutive relationships. These constitutive relationships must objectively reflect the relationships between microscopic physical quantities, but the constitutive relationships obtained through mathematical methods may be not physically realizable, or conflict with the generally acknowledged truths (such as energy conservat…